Hydraulic control valves, which are widely applied to hydraulic systems, are used to control direction, pressure and flow of fluid, and significantly influence many industrial movable equipments (such as various machines and vehicles) using hydraulic transmission system.
Traditionally, there are three kinds of hydraulic valves including directional control valves, pressure control valves and flow control valves. One representative kind of these products is plate connection hydraulic control valves having 2 ports (such as check valves, hydraulic control check valves, overflow valves, relief valves, throttle valves, speed adjust valves and so on). According to the technical principles, they are also known as “single element” products. Due to historical reasons, the “single element” valves not only possess simplex function, but also have different internal and external structures along with unnecessary differentiation and distinct discretization. So the higher level of the technology, the more inconvenient they are. For example, when a function of any hydraulic valve in hydraulic systems is changed, it needs to change and redesign the hydraulic system and valve block body as well as supply chain procedure, raising costs, and postponing shipment. Unnecessary differentiation and discretization in the structures and shapes of these products usually cause significant changes in the whole manufacturing process and supply chain procedures, thus, resulting in resource waste, raising production costs as well as the total costs of product. This kind of valves are not suitable for fast-growing technical environment and can not meet requirements for modularization and integration of product structure in modern control technology.